Pipe bending machine for industrial piping



Nov. 20, 1956 s. L. BALLARD PIPE BENDING MACHINE FOR INDUSTRIAL PIPING 4Sheets-Sheet 1 Filed Oct. 26 1951 30/77 L. 50//c1r0 INVENTOR BY QVJUQ M,4 TTORA/EKS Nov. 20, 1956 s. BALLARD PIPE SENDING MACHINE FORINDUSTRIAL PIPING Filed Oct. 26. 1951 4 Sheets-Sheet 2 l8 7 4rfni l i 1IO 459-13 Jam L. BQHQ/Q INVENTOR. 1/21. 53m ZQ K 2J7 H yaZ/M/ Nov. 20,1956 s. BALLARD 2,771,116

PIPE BENDING MACHINE FOR INDUSTRIAL PIPING Filed Oct. 26. 1951- 4Sheets-Sheet 3 J00? L. Sofia/'0 INVENTOR.

39:8 43 29 y /d w 32 9 2d A TTORNEYS Nov. 20, 1956 s. L. BALLARD PIPESENDING MACHINE FOR INDUSTRIAL PIPING 4 Sheets-Sheet 4 Filed Oct. 26.1951 Sam L. Ba//ard INVENTOR. 202.51

ATTORNEYS United States Patent" PEPE BENDING MACHINE FOR INDUSTRIALPIPING Sam L. Ballard, Houston, Tex.

Application October 26, 1951, Serial No. 253,336

8 Claims. (Cl. 153-45) This invention relates to a method of bendingpipe, and to pipe bending machines for carrying out such method and moreparticularly to such pipe bending machines adapted to bend industrialpipe, such as pipe used in ships, plants, and refineries, and suchinvention particularly relates to pipe bending machines in which forceis applied to a straight bending shoe to force a portion of the pipe tobe bent around to the curvature of the bend forming face portion of acurved bending die while the other end of the pipe is restrained in arockably mounted holding shoe.

It is therefore an object of this invention to provide a method ofbending pipe under space limitations, and also to provide machines forcarrying out such bending.

It is also an object of this invention to provide pipe bending machinesof this class which have a straight bending shoe to which force isapplied to force a portion of the pipe to be bent around to thecurvature of the bend forming face portion of a curved bending die whilethe other end of the pipe is restrained in a rockably mounted holdingshoe.

It is another object of this invention to provide pipe bending machinesof this class which have means to apply force to urge a part of theholding shoe directly toward the die to tightly embrace the pipe andalso means to apply force beyond the die on the opposite side thereoffrom the holding shoe to roll the bending shoe along the die while it isheld in such pipe embracing relation with the die.

It is a still further object to provide pipe bending machines of thisclass having actuating means for the two forces acting on the strongbackto cause said forces to act conjointly on the bending shoe.

it is also a further object of this invention to provide pipe bendingmachines of this class in which the actuating means operates around aseries of davits spaced to sucly constructed, have few moving parts, andwhich can be installed in a pipe shop on a single slab.

It is yet a further object of this invention to provide a pipe bendingmachine of this class in which a bridle connects the member forcing thepipe into an embraced position between bending shoe and bending die withthe end portion of the bending shoe on the opposite side of the memberfrom the holding shoe, such bridle passing through a bridle blockinterposed between its end connections.

It is also a still further object of this invention to provide a pipebending machine of this class which may employ a multiplicity of reevedSheaves in the bridle block and davit members to multiply the bendingforce applied to the bridle.

It is yet another object of this invention to provide a pipe bendingmachine of this class having its bridle block connected by a lineremovably extending around a series force.

It is still a further object of this invention to provide a pipe bendingmachine of this class which has a straight bending shoe which contactsthe bending die as it moves therearound to bend the pipe embracedbetween the die and the shoe.

It is also an object of this invention to provide a pipe bending machineof this class which has a straight bending shoe which is spaced from thebending die as it moves around the pipe embraced between the die and theshoe to bend the pipe.

It is yet a further object of this invention to provide a pipe bendingmachine of this class which has a straight bending shoe spaced on eitherside of the central portion of a curved bending die; each bending shoebeing operable responsive to the application of force thereto to bend aportion of a pipe into the bend forming face portion of the bending shoeso that the shoes operate together to bend the pipe to the curvature ofthe die.

It is also another object of this invention to provide a pipe bendingmachine of this class adapted to bend pipe in either a horizontal orvertical plane.

t is yet a further object of this invention to provide a method ofbending pipe with a machine of this class by which method the line frombridle block to winch is successively removed from the davit nearest thebridle block as bending progresses.

It is still another object of this invention to provide a pipe bendingmachine of this class operable with two bending shoes, which providesmeans between the inner ends of the shoes to move in and grasp thecentral pipe portion between the shoes to prevent this portion fromwrinkling.

It is still another object of this invention to provide a rapid methodof bending pipe by employing two force applying means outwardly and twoforces inwardly thereof to contact the pipe with the curved bending die,the outward forces serving to bend the pipe from its center portionoutwardly at each end into a curved die.

Other and further objects will be apparent when the specification isconsidered in connection with the drawings in which:

Fig. l is a plan view of the machine in initial position to beginbending pipe.

Fig. 1A is a fragmentary plan view of another modification of themachine which modification has special application in the bending ofthick walled pipe.

Fig. 2 is a plan view of the machine as bending progresses.

F Fig. 3 is a sectional elevation taken along line 3-3 of Fig. 4 is aperspective view of the pipe contacting elemerits and of the points offorce application.

Fig. 5 is a plan view of a smaller size pipe bending machine showing amodification of the employment of the actuating means.

Fig. 6 is a view of a modification of a pipe bending machine of thisclass in which two straight bending shoes are employed, one on eitherside of the central portion of the bending die.

Fig. 7 is a sectional view taken along line 7-7 of Fig. 6.

Fig. 1 shows a machine 1 which includes a slab 2 on which it isgenerally mounted. Such machine has a base 3 which may be embedded inthe slab or mounted rigidly thereon. Brackets 4 connect this base 3 tothe support or body portion 5' of the bending die 5, and these bracketsalso support and space the die 5 from the slab 2.

The die is substantially semi-circular in shape, and the peripheral face6 is formed to receive substantially the semi-peripheral surface of apipe to be bent. The holding shoe or strap 7 is pivot-ally or rockablymounted at 8 to the die and is curved, as shown in Fig. 4 to extendaround one end portion 9 of the pipe 10 which is to be out.

The shackle 11 has the arms 12 and 13 thereof pivotally mounted to thepin 16 at the center of the die 5 and has the roller 14 between the arms12 and 13 with the roller shaft 15 journalled at either end in thesearms. At the outer end 17 of the shackle, the bar 13 is connected towhich may be connected one end 19 of the bridle 20.

The straight bending shoe 21 is of a cross-section to provide a bendforming face portion 22 to receive substantially the semi-periphery ofthe pipe 10 to be bent, and to complement the die 5 in embracing thepipe, and is of a wall thickness so that the shoe end 23 will becontacted by the roller 14. The bridle may then be threaded through thesheave 24 of the bridle block 25 and the end 26 of the bridle 20connected to the bar 27 on the outer end 28 of the bending shoe 21 intowhich the outer portion 29 of the pipe 10 extends.

A series of davits 39, 31, 32, and 33 are mounted on the slab 2 and therotatable members 34 thereof on the upstanding studs 35 receive the line36 t hereagainst. This line has one end portion 37 connected at 33 intothe bridle block 25. The other end portion 39 of the line 36 is woundaround the drum 40 of the winch 41 and anchored thereto. Conventionalpower means, not shown, actuates the winch to wind up the line 36thereon.

It can thus be seen that when the winch 41 is actuated to wind up theline 36 to draw the bridle block 25 toward the first davit, the holdingshoe or strap 7 will initially pivot or rock about the pin 8, anindicated in Fig. 2. As this happens, the shackle 11, which is pulled bythe portions 42 of the bridle 20, forces the roller 14 against thebending shoe portion 23. At the same time the portions 43 of the bridlepull upon the outer end 29 of the bending shoe 21 to apply the leverageto the shoe 21 which acts to bend the pipe 10.

As shown in Figs. 1 and 3, the sides 44 of the bending shoe and sides 45of the bending die are in contact with each other at a point of contactwhich changes constantly as the bending shoe is rolled without slippagealong the pipe and die to bend the pipe.

It can thus be considered that two force applying means act conjointlyon the bending shoe to bend the pipe. One such force applying means actsat any point of time on the opposite side of the holding shoe from thecentral point of the instantaneously effective bending portion of thebending shoe to urge a part of the bending shoe directly toward the dieto tightly embrace the pipe held therebetween. This force applying meanshas, in the form of the inner portions 47 of the shackle arms 12 and 13,spaced independent swinging connections to the support portion 5' forthe bend forming face portion 6 of the die 5. Also, via the roller 14,the central portions 48 of these arms constitute spaced independentswinging connections to the bending shoe 21.

The other such force applying means acts beyond the die and on theopposite side thereof from the holding shoe to roll the bending shoealong the die while it is held in pipe embracing position. Such forceapplying means has, in the form of the bridle portions 43, the bridleblock 25, the line 36, the davits, :and via the winch 41, spacedindependent swinging connections to the slab 2, which together with thebase 3, brackets 4, and body portion 5' of the die, may be considered toform the support or rigid frame portion of the machine 1.

When the winch 41 is rotated by its driving means, not shown, suchdriving means, abetted by the bridle portions 42, which tie the twoforce applying means together to act conjointly, serve as the actuatingmeans operable to cause the two force applying means to act conjointlyon the bending shoe to bend the pipe.

In general, the machine of this invention follows this type of machinein that this machine employs a comparatively long, straight bendingshoe, and a curved bending die. A rockabie holding shoe or anchor memberholds one end of the pipe, and on the opposite side of this holding shoefrom the central portion of the instanteous active bending portion ofthe die, one force acts to hold, or force the shoe against the pipe andtoward the die, and outwardly from the first force, and on the oppositeside of the die from the holding shoe, a second force acts conjointlywith the first force and toward the end of the shoe, to roll the shoearound the pipe as it bends the pipe into the curvature of the die.

It is pointed out that the above described relationship, as comparedwith the presently employed strongback or straight bending shoe typepipe bending machine, holds even though the bridle portion 42 and thebridle portion 43 are constantly changing in length, and also the ratioof the lengths of the portions to each other is gradually changing.

It is also noticeable that, as bending progresses, the line 36 can beslacked and lifted successively from the davits 3t), 31, and 32, so thatbends of considerable arc can be accomplished.

It is also pointed out that whereas the bridle block 25 and line 20 aredisclosed, such could be removed, and any two separate forces applied,one to the shackle and one to the end 28 of the shoe 21, and the theoryof this invention could be employed by the co-ordination of such forcesto bend the pipe.

As the winch 41 is of limited power delivery, and as the wall thicknessand strength of various pipe varies widely, with a winch of ratedcapacity, it may be possible to bend thin walled pipe or relative weakpipe by using the form of invention shown in Figs. 1-4; the same winchmight not be able to bend extra strong pipe, or comparatively thickwalled pipe, as a fair part of the developed force is dissipated in thefrictional contact between the die surfaces 45 and shoe surfaces 44.

However, if the modification of machine shown in Fig. 1A is employed, inwhich the peripheral length of the bend forming face portion of the shoeand the die are slightly less than the circumference of the pipe, sothat the surfaces 44' and 45 do not come in contact, then the powerdissipated in the modification of Figs. 14 in contact between the shoeand the die, is saved in this modification of Fig. 1A, so thatsubstantially all of the bending power is employed to bend the pipe.

it is also possible to gain mechanical advantage in bending, as shown inS, by reeving the line 36 a plurality of times through the bridle block25 and around the davit in use adjacent the bridle block. This can bedone when required by disconnecting the end 37 of the line 36 from thebridle block at 33, making the extra desired turns through the sheaves24 and around the davit, and then reconnecting the end of the line. Inthis regard it is obvious that the bridle block 25 must have a pluralityof sheaves or grooves, as is conventional, and therefore nocrosssectional view is taken through the block to show this feature.

The modification of this invention employed in Figs. 6 and 7 shows amachine 5'!) having a frame 5'1 on which may be mounted the winches 52,52', or optionally a single winch, not shown, may be geared or otherwiseconnected to drive two drums 52, 52, in the directions im 2' cated. Thecentral support beam or column 53 extends fromthe frame 51 to supportthe curved die 54 which is rigidly connected to the column 53 at itscentral portion. This curved die has the bend forming face portion toreceive substantially the semi-periphery of the pipe to be bent.

The shackles 56 and 57 are pivotally connected to the pins 53 and 59which extend from the column 53, and the rollers 66! and 61 thereofsupport the inner ends 62 and 63 of the straight bending shoes 64 and 65having the bend forming face portions These shoes 61 and 655 have thesheave blocks 66 and 67 on their outer cud 6t; and 69.

A line 70 from the winch 52 is reeved through the block 66 and throughthe block 71 on the plate 72 which is rigidly connected to the frame 51and column 53. The line 70 then may pass back through the block 66 andthen through the sheave block 66, back again through the block 73, andback to a final dead end 75 at the block 66. The line 76 from the winch52' is similarly reeved through the block 67 on the shoe 65, the block77 on the plate 79, and the block 80 on the shackle 57.

In order to insure against the central portion of the pipe fromwrinkling as the straight shoes or strongbacks bend the pipe, thecentral die portion 81 is provided to move into grasping contact withthe pipe as bending progresses. This may be accomplished by a number ofstructures, as a hydraulic ram, which moves the die into the spacebetween the inner ends of the strongbacks and against the entral portionof the pipe. Another structure for this purpose may consist of sheaveblocks or pulleys located on the die portion 81 and connected by a linepassing through other blocks or pulleys on the frame 1 and finallycorrelated with, and actuated by, the prime mover of the winches ordrums 52, and 52'.

In the form of device for this purpose disclosed in the drawingslinkages 82, 83 are pivotally connected at their inner ends to the pins84 on each side of the die portion 81, and at their outer ends to thepivot pins 85 and 86 on either side of the strongbacks or bending shoes64 and 65. A guide sleeve 87 is provided on either side of the curveddie 54 to receive the guide rods 88 connected on either side of the dieportion 81.

This modification is designed to provide more rapid bending, by bendingtwo portions of a pipe at once and is also designed to bend pipe to agreater degree of bend at a greater speed than can be accomplished withsome of the other forms of machines operable on the strongbackprinciple.

In this machine the anchor 7 is eliminated since the strongbacks 64 and65 act on either side of the central point of the bend forming faceportion 55 so that the pipe section between the inner ends thereof isrestrained from motion.

Broadly, this invention covers a pipe bending machine operable on thestrongback principle which is adapted to bend industrial pipe. In thisregard it is pointed out that the relative positions of the elements inthese machines can be reversed, that is, the machines of. Figs. 1-5 canbe shaped to operate in a vertical plane and the machine of Figs. 6 and7 can operate in a horizontal plane. Also, each machine can operate withthe strongback rolling in contact with the curved die, or rolling aboutthe pipe and spaced from the curved die.

What is claimed as new is:

l. A pipe bending machine comprising a support, a rigid die anchored onthe support and having a working face with a bend forming portion shapedto conform to the curvature of the inside of the bend to be produced ina pipe, a rockably mounted holding shoe on the support opposed to thecurved die adjacent one end thereof and movable toward and away from thecurved die, a separate independently mounted rigid bending shoe shapedto conform to the shape of the pipe before bending and in initialposition before bending of the pipe having a first part directly opposedto the bend forming portion of the working face of the curved die andextending past the central point of the face of the die toward theholding shoe and a second part located and extending a substantialdistance beyond the bend forming portion of said face in a directionaway from said holding shoe, shackle means pivotally connected inwardlyto said support and including means thereon adapted to maintain rollingcontact with the surface of said shoe first part opposite the bendforming face portion thereof, a line connected at a first end to saidshoe at substantially the end of said second part, a bridle block, saidline extending from said first end through said bridle block andconnected at the other end thereof to said shackle outwardly of saidrolling contact means, and power means connected to said bridle blockand adaptedto pull upon said bridle block as said bridle block slidesalong said line, the pull of said power means as transmitted throughsaid bridle block to said other end causing said rolling contact meansof said shackle to force said shoe first part toward the die to causethe bending shoe and die to tightly embrace a pipe at the locus ofbending during the bending operation while permitting the bending shoeto roll in contact with said die, said pull of said power means astransmitted through said bridle block to said first end actingtransversely of said bending shoe in a direction to roll said bendingshoe along said die to bend the pipe into said bend forming face portionof said die.

2. A pipe bending machine comprising a support, a rigid die anchored onthe support and having a working face with a bend forming portion shapedto conform to the curvature of the inside of the bend to be produced ina pipe, a rockably mounted holding shoe on the support opposed to thecurved die adjacent one end thereof and movable toward and away from thecurved die, a separate independently mounted rigid bending shoe shapedto conform to the shape of the pipe before bending and in initialposition before bending of the pipe having a first part directly opposedto the bend forming portion of the working face of the curved die andextending past the central point of the face of the die toward theholding shoe and a second part located and extending a substantialdistance beyond the bend forming portion of said face in a directionaway from said holding shoe, shack-1e means pivotally connected inwardlyto said support and including means thereon adapted to maintain rollingcontact with the surface of said shoe first part opposite the bendforming face portion thereof, a line connected at a first end to saidshoe at substantially the end of said second part, a bridle block, saidline extending from said first end through said bridle block andconnected at the other end. thereof to said shackle outwardly of saidrolling contact means, and power means connected to said bridle blockand adapted to pull upon said bridle block as said bridle block slidesalong said line, the pull of said power means as transmitted throughsaid bridle block to said other end causing said rolling contact meansof said shackle to force said shoe first part toward the die to causethe bending shoe and die to tightly embrace a pipe at the locus ofbending during the bending operation while permitting the bending shoeto roll in spaced relation from said die, said pull of said power meansas transmitted through said bridle block to said first end actingtransversely of said bending shoe in a direction to roll said bendingshoe along said die to bend the pipe into said bend forming face portionof said die.

3. A pipe bending machine comprising a support, a rigid die anchored onthe support and having a working face with a bend forming portion shapedto conform to the curvature of the inside of the bend to be produced ina pipe, a rockably mounted holding shoe on the support opposed to thecurved die adjacent one end thereof and movable toward and away from thecurved die, a separate independently mounted rigid bending shoe shapedto conform to the shape of the pipe before bending and in initialposition before bending of the pipe having a first part directly opposedto the bend forming portion of the working face of the curved die andextending past the central point of the face of the die toward theholding shoe and a second part located and extending a substantialdistance beyond the bend forming portion of said face in a directionaway from said holding shoe, shackle means pivotally connected inwardlyto said sup-' port and including means thereon adapted to maintainrolling contact with the surface of said shoe first part opposite thebend forming face portion thereof, a line connected at a first end tosaid shoe at substantially the end of said second part, a bridle block,said line extend v ing from said first end through said bridle block andconnected at the other end thereof to said shackle outwardly of saidrolling contact means, and power means connected to said bridle blockand adapted to pull upon said bridle block as said bridle block slidesalong said line, the pull of said power means as transmitted throughsaid bridle block to said other end causing said rolling contact meansof said shackle to force said shoe first part toward the die to causethe bending shoe and die to tightly embrace a pipe at the locus ofbending during the bending operation while permitting the bending shoeto roll around said die, said pull of said power means as transmittedthrough said bridle block to said first end acting transversely of saidbending shoe in a direction to roll said bending shoe along said die tobend the pipe into said bend forming face portion of said die.

4. A pipe bending machine comprising a support, a rigid die anchored onthe support and having a working face with a bend forming portion shapedto conform to the curvature of the inside of the bend to be produced ina pipe, a rockably mounted holding shoe on the support opposed to thecurved die adjacent one end thereof and movable toward and away from thecurved die, a separate independently mounted rigid bending shoe shapedto conform to the shape of the pipe before bending and in initialposition before bending of the pipe having a first part directly opposedto the bend forming portion of the working face of the curved die andextending past the central point of the face of the die toward theholding shoe and a second part located and extending a substantialdistance beyond the bend forming portion of the face in a direction awayfrom said holding shoe, shackle means pivotally connected inwardly tosaid support and including means thereon adapted to maintain rollingcontact with the surface of said shoe first part opposite the bendforming face portion thereof, a line connected at a first end to saidshoe at substantially the end of said second part, a bridle block, saidline extending from said first end through said bridle block andconnected at the other end thereof to said shackle outwardly of saidrolling contact means, and power means connected to said bridle blockand adapted to pull upon said bridle block as said bridle block slidesalong said line, the pull of said power means as transmitted throughsaid bridle block to said other end causing said rolling contact meansof said shackle to force said shoe first part toward the die to causethe bending shoe and die to tightly embrace a pipe at the locus ofbending during the bending operation while permitting the bending shoeto roll around said die, said pull of said power means as transmittedthrough said bridle block to said first end acting transversely of saidbending shoe in a direction to roll said bending shoe along said die tobend the pipe into said bend forming face portion of said die, saidpower means including a second line connected at one end to said bridleblock, and a winch around which the other end of said line is wound andto which the other end of said line is con nected, said machineincluding a series of davits about which said second line may pass andfrom which said second line is successively disengaged as the bending ofthe pipe progresses.

5. A pipe bending machine comprising a support, a rigid die anchored onthe support and having a working face with a bend forming portion shapedto conform to the curvature of the inside of the bend to be produced ina pipe, means for holding a portion of the pipe to be bent in fixedrelation to said die while another portion is being bent therearound, aseparate independently mounted, rigid bending shoe shaped to conform tothe shape of the pipe before bending and having a first part directlyopposed to the section of the bend forming portion of the working faceof the curved die which will first have the pipe bent therein and asecond part located and extending a substantial distance beyond saidfirst section, shackle means pivotally connected inwardly to saidsupport and including means thereon adapted to maintain rolling contactwith the surface of said shoe first part opposite the bend forming faceportion thereof, a line connecting said second part and said shackleoutwardly of said rolling contact means, means providing a slidingconnection to said line, and power means adapted to pull upon said linethrough said sliding connection to cause said rolling contact means ofsaid shackle to force said shoe first part toward the die to cause thebending shoe and die to tightly embrace a pipe at the locus of bendingduring the bending operation while permitting the bending shoe to rollaround said die, said pull of said power means as transmitted throughsaid line to said second part acting transversely of said bending shoein a direction to roll said bending shoe along said die to bend the pipeinto said bend forming face portion of said die.

6. In a pipe bender, a stationarily mounted curved bending die having abend forming face portion, means cooperating with said die to hold aportion of a pipe to be bent in fixed relation to said die, a rigidbending shoe shaped to conform to the shape of the pipe before bendingwith one end adjacent said pipe holding means in initial position beforebending of the pipe and the other end extending along the portionthereof to be bent, a shackle mounted to swing about a fixed pivot atthe center of curvature of said die and extending radially beyond saidone end of said bending shoe and having means engaging said shoe to holdit against outward movement away from said die, and force applying meansoperatively connected to said shackle and to said shoe at a fixedposition spaced from said one end thereof for conjointly swinging saidshoe around said die to bend said pipe and said shackle means to holdsaid shoe against movement away from said die at the locus of bending.

7. The invention, as set forth in claim 6, wherein means for connectingthe force applying means to the shackle and shoe includes a lineinterconnecting the outer end of the shackle and the other end of theshoe, and means for maintaining said line under tension as said outerend of said shackle approaches said other end of said shoe while thebending operation is being performed.

8. In a pipe bender, a stationarily mounted curved bending die having abend forming face portion, means cooperating with said die to hold aportion of a pipe to be bent in fixed relation to said die, a rigidbending shoe shaped to conform to the shape of the pipe before bendingwith one end adjacent said pipe holding means in initial position beforebending of the pipe and the other end extending along the portionthereof to be bent, a shackle mounted to swing about a fixed pivot atthe center of curvature of said die and extending radially beyond saidone end of said bending shoe and having means engaging said shoe to holdit against outward movement away from said die, a line connected to saidshackle and to said shoe at a position spaced from said one end thereof,means providing a sliding connection to said line, and force ap plyingmeans connected to said sliding connection means for tensioning saidline and conjointly swinging said shoe around said die to bend said pipeand said shackle means to hold said shoe against movement away from saiddie at the locus of bending.

References Cited in the file of this patent UNITED STATES PATENTS1,349,219 Moore et al Aug. 10, 1920 1,662,131 Schonfield Mar. 13, 19281,741,840 Harmon et al Dec. 31, 1929 1,957,395 Kirchner May 1, 19342,347,593 Cummings Apr. 25, 1944 FOREIGN PATENTS 2,538 Great Britain of1903 232,179 Germany Dec. 23, 1908 208,913 Germany Apr. 13, 1909 565,395Germany Nov. 30, 1932

